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Douglas R Dirschl

Publications and source records attributed to Douglas R Dirschl.

At least 19 recordsLinked to original sources
PubMed2006

Correlation of transfusion volume to change in hematocrit.

While it has generally been accepted that a 3% change in hematocrit is equivalent to a 1-"unit" loss of blood, few studies have been published to actually document this. A more complete understanding of this correlation would be helpful in estimating blood loss from changes in hematocrit in patients sustaining hemorrhage as well as in those receiving transfusions. In this retrospective study, we analyzed the post-transfusion alterations in hematocrit from 61 independent transfusions in 48 different pelvic fracture patients (age range, 16-62 years). Transfusion volumes were correlated with changes in hematocrit over 24-hr periods between the 5th and 12th hospital days, a time when there was no ongoing hemorrhage in these patients. The average increase in hematocrit per liter of packed red blood cells transfused was 6.4% +/- 4.1%. If 1 "unit" of packed red blood cells is approximately 300 mL, this becomes a change of hematocrit of 1.9% +/- 1.2% per "unit" of blood. The accepted correlation of about 1 "unit" of blood loss per 3% change in hematocrit would be valid for a 500-cc unit, but a typical unit of packed red blood cells is typically 300 cc. In addition, the variability is substantial as indicated by our standard deviation. Limitations of this study include hematocrit changes due to fluid resuscitation, dehydration, age, persistent hemorrhage, and the retrospective nature of the evaluation.

Adolescent↗
PubMed2006

Effects of varying pulsatile lavage pressure on cancellous bone structure and fracture healing.

OBJECTIVE: To study the effects of variations in pulsatile lavage irrigation pressure on the rate of new bone formation and the degree to which cellular elements are removed from cancellous bone after fracture. DESIGN: A previously described intraarticular fracture model was used for 29 New Zealand white rabbits that underwent osteotomy of the medial femoral condyle. Fractures were irrigated with high-pressure pulsatile lavage at a fixed distance and volume, but at nozzle pressures varying from 20 to 70 psi. Fractures were reduced and stabilized, and animals euthanized 14 days after fracture. Fluorescent bone staining was used to determine the rate of new bone formation in the osteotomy site. At the time of euthanasia, the nonoperated knees of 12 rabbits underwent osteotomy and irrigation using the same protocol. These specimens were sent for immediate scanning electron microscopy to determine the amount of cellular material removed from the bony trabeculae. RESULTS: In the first week after irrigation, there was no significant difference in the amount of new bone formation between the 20- and 30-psi groups, but there were significant differences between these groups and the 50- and 70-psi groups. There were no significant differences between any of the groups in the amount of new bone formed during the second week after irrigation. No structural damage to the bony trabeculae was observed in any specimen irrigated at any of the pressures used. There was a direct correlation between percentage of the trabecula completely cleared of cellular material and irrigation pressure; there were statistically significant differences between each of the groups. CONCLUSIONS: There are presently no recommended guidelines as to the optimal irrigation pressure, and this study is the first to address the effects of variations in pressure on bone healing. The results of this study indicate that early new bone formation in an intraarticular fracture rabbit model is inhibited by irrigation pressure of 50 psi or greater. Additionally, this study demonstrates a direct relationship between irrigation pressure and the amount of cellular material removed from the trabecula at the irrigation site. Surgeons should be aware of the potentially detrimental effects of using irrigation pressures at or above 50 psi in the treatment of fractures.

Animals↗
PubMed2006

Resident selection and predictors of performance: can we be evidence based?

Selection of orthopaedic residents can be a difficult process; we have endeavored to make it more objective by developing a scoring methodology for screening applications. The purpose of this investigation is to determine if an academic score, using objective elements only, will discriminate among applicants and will correlate with outcomes. Applications to our orthopaedic residency program for 2004 and 2005 were assigned an academic score as a screening tool in the residency selection process. Data was analyzed for the entire group both by gender and whether the applicant had interviewed for the program. Additionally, the applications of program graduates over the past 5 years were retrospectively assigned academic scores, which were compared with outcomes of the training program. Academic scores for applicants formed a generally normal distribution, and residents training in the program generally had higher scores. The distribution of scores for female applicants was similar to male applicants; however, a greater percentage of female applicants interviewed for the program. Scores on the OITE and ABOS examinations tended to parallel academic scores, but faculty ratings of performance in the program showed no difference between those with high and low academic scores. Calculating academic scores makes the application screening process more objective but does not appear to correlate with outcomes of the training program.

Clinical Competence↗
PubMed2006

Reliability of classification of fractures of the tibial plafond according to a rank-order method.

BACKGROUND: Many orthopedic classification systems, including those for tibial plafond fractures, are either unvalidated or have demonstrated problems with interobserver reliability. Classification of tibial plafond fractures according to a rank-order method has shown excellent interobserver reliability with several observers. The purpose of this study is to determine the reliability of a rank order classification of plafond fractures with a large number of observers. METHODS: A radiographic review study was completed by 69 orthopedists of varying training levels. Observers ranked 10 fractures of the tibial plafond based on anteroposterior and lateral ankle radiographs. Fractures were ranked in increasing severity from 1 to 10. No instructions were given regarding determination of severity. Agreement between rankings was analyzed by the intraclass correlation coefficient (ICC). RESULTS: Rankings were performed by viewing prints at the annual Orthopaedic Trauma Association meeting and through the Orthopaedic Trauma Association website using digital images. The overall ICC was 0.62. There was no difference in the ICC between traumatologists and general orthopedists (p > 0.5). Eleven observers commented that the radiographs did not represent the full spectrum of injury severity. CONCLUSIONS: The interobserver reliability of the rank-order classification in this study was fair to good, which is better than previously reported for plafond fracture classification systems. It remains to identify and validate a series of tibial plafond fractures that represent a full spectrum of injury and can be ranked with excellent interobserver reliability. A series of cases such as this may then serve a measurement standard for severity of bony injury against which individual cases may be reliably compared.

Classification↗
PubMed2005

Interobserver reliability of a CT-based fracture classification system.

OBJECTIVES: This study was designed to determine whether the interobserver reliability of a fracture classification scheme applied based on a single, carefully defined, computed tomography (CT) cut is greater than those previously reported for systems designed for use with plain radiographs. DESIGN: Observer review of selected cases. SETTING: Four, level one, trauma centers. PATIENTS: Pretreatment CT scans of patients with calcaneus fractures were screened by the authors. Thirty cases were selected that had an appropriate semicoronal CT image. Ten orthopaedic traumatologists who were members of the Orthopaedic Trauma Association and had a minimum of 5 years postresidency experience were selected as reviewers. INTERVENTION: The reviewers were provided with a digital CT image for each case as well as written and diagrammatic representations of the Sanders classification system. The observers then classified each fracture according to the Sanders classification. RESULTS: : The mean kappa value for interobserver reliability for fracture types I-IV was 0.41 +/- 0.02 (mean +/- standard error of the mean; range, 0.07-0.64). Observers disagreed by more than 1 fracture type (ie, I vs. III or II vs. IV) in 10% of the cases. Observers agreed on the location of the fracture lines (A, B, C) in 90% of type II fractures and 52% of type III fractures. CONCLUSIONS: The results indicate that in a carefully controlled paradigm, the interobserver reliability with a classification system based on interpretation of a single, carefully defined CT image was no better than the results reported for the same classification system used with full CT data or for other classification systems used for various fractures in the skeleton. Agreement in identifying the location of the fracture lines was very good for simple fractures but much worse for complex injuries. Additional study may determine whether the use of a full complement of CT images can improve reliability in classification of complex injuries.

Ankle Injuries↗
PubMed2004

Factors affecting outcome in tibial plafond fractures.

To determine what fracture- and patient-specific variables affect outcome, 29 patients with 32 tibial plafond fractures were evaluated at a minimum of 2 years from the time of injury (range, 24-129 months; average, 46.5 months). The rank order method was used to assess severity of injury and accuracy of articular reduction on radiographs and agreement among the five surgeons was excellent with intraclass correlation coefficients of 0.93 and 0.94. Outcome was assessed by four independent measures: a radiographic arthrosis score, a subjective ankle score, the Short Form-36 (SF-36), and the patient's ability to return to work. The four outcome measures did not correlate with each other. Radiographic arthrosis was predicted best by severity of injury and accuracy of reduction. However, these variables did not show any significant relationship to the clinical ankle score, the SF-36, or return to work. These outcome measures were more influenced by patient-specific socioeconomic factors. Higher ankle scores were seen in patients with college degrees and lower scores were seen in patients with a work-related injury. The ability to return to work was affected by the patient's level of education. This study highlights the difficulties of predicting patient outcome, after these severe articular fractures.

Adolescent↗
PubMed2004

Injury severity assessment in tibial plateau fractures.

Assessment of injury severity is an integral component of the care of the patient with a fracture of the tibial plateau. Devising ways to reliably quantify injury severity, and to make predictive links between injury severity and outcome, however, has been difficult. Assessment of patient-related factors, such as age, functional capabilities, and medical comorbidities, are necessarily subjective, but certain of these factors clearly shape the treatment plan for a patient with a tibial plateau fracture. Clinical examination findings, such as extent of soft tissue injury and mediolateral stability of the knee, also play an important role in determining treatment and predicting outcome. Radiographic classification of tibial plateau fractures also is an important determinant of treatment, but current classification systems have suffered from disappointing interobserver reliability. Although the severity of injury to the articular cartilage almost certainly affects outcome, there currently are no validated modalities to measure this important factor. More carefully validated tools are needed in many of these areas if we are to perfect our understanding of injury severity and establish more accurate correlations between injury severity and outcomes.

Cartilage, Articular↗
PubMed2003

Internal fixation versus arthroplasty of comminuted fractures of the distal humerus.

BACKGROUND: A comminuted distal humerus fracture in an older patient is a difficult clinical problem. Open reduction internal fixation (ORIF) carries the risks of nonunion, loss of fixation, infection, and stiffness. Arthroplasty carries the risks of loosening, infection, and periprosthetic fracture. Both procedures are technically challenging, and complications following these procedures are frequent. OBJECTIVE: To evaluate best available evidence to assist in guiding clinical decision making for ORIF versus arthroplasty of intraarticular distal humeral fractures in elderly patients. HIGHEST AVAILABLE EVIDENCE: 1. Case series of internal fixation or arthroplasty of acute interarticular distal humerus fractures in the elderly (level IV). 2. Review of expert opinion without explicit critical appraisal or controlled research (level V). STUDY IDENTIFICATION: 1. Computerized data search 1969-2003, Cochrane Database, OVID Search Engine. 2. Reviews of bibliographies of selected articles.

Aged↗
PubMed2003

Designing, conducting, and evaluating journal clubs in orthopaedic surgery.

The first record of a journal club was that founded in 1875 by Sir William Osler at McGill University for the purchase and distribution of periodicals to which he could not afford to subscribe as an individual. Evidence-based medicine is becoming an accepted educational paradigm in medical education at various levels. An analysis of the literature related to journal clubs in residency programs in specialties other than orthopaedic surgery reveals that the three most common goals were to teach critical appraisal skills (67%), to have an impact on clinical practice (59%), and to keep up with the current literature (56%). The implementation of the structured article review checklist has been found to increase resident satisfaction and improves the perceived educational value of the journal club without increasing resident workload or decreasing attendance at the conference. Periodic evaluation of the conference and the institution of appropriate changes ensures that the journal club remains a valuable and successful part of the training program.

Curriculum↗
PubMed2003

Tibial plafond fractures. How do these ankles function over time?

BACKGROUND: The intermediate outcome of fractures of the tibial plafond treated with current techniques has not been reported, to our knowledge. The purpose of this study, performed at a minimum of five years after injury, was to determine the effect of these fractures on ankle function, pain, and general health status and to determine which factors predict favorable and unfavorable outcomes. METHODS: Fifty-six ankles (fifty-two patients) with a tibial plafond fracture were treated with a uniform technique consisting of application of a monolateral hinged transarticular external fixator coupled with screw fixation of the articular surface. Thirty-one patients with thirty-five involved ankles returned between five and twelve years after the injury for a physical examination, assessment of ankle pain and function with the Iowa Ankle Score and Ankle Osteoarthritis Scale, assessment of general health status with the Short Form-36 (SF-36), and radiographic examination of the ankle. RESULTS: Arthrodesis had been performed on five of the forty ankles for which the outcome was known at a minimum of five years after the injury. Other than removal of prominent screws (two patients), no other surgical procedure had been performed on any patient. The average Iowa Ankle Score was 78 points (range, 28 to 96 points). The scores on the SF-36 and Ankle Osteoarthritis Scale demonstrated a long-term negative effect of the injury on general health and on ankle pain and function when compared with those parameters in age-matched controls. The degree of osteoarthrosis was grade 0 in three ankles, grade 1 in six, grade 2 in twenty, and grade 3 in six. The majority of patients had some limitation with regard to recreational activities, with an inability to run being the most common complaint (twenty-seven of the thirty-one patients). Fourteen patients changed jobs because of the ankle injury. Fifteen ankles were rated by the patient as excellent; ten, as good; seven, as fair; and one, as poor. Nine patients with previously recorded ankle scores had better scores after the longer follow-up interval. The patients perceived that their condition had improved for an average of 2.4 years after the injury. CONCLUSIONS: Although tibial plafond fractures have an intermediate-term negative effect on ankle function and pain and on general health, few patients require secondary reconstructive procedures and symptoms tend to decrease for a long time after healing.

Adult↗
PubMed2002

High-pressure pulsatile lavage irrigation of contaminated fractures: effects on fracture healing.

To evaluate the effects of high-pressure pulsatile lavage (HPPL) irrigation on new bone formation and fracture union in a contaminated intraarticular fracture, 45 New Zealand white rabbits were divided into three equal groups. The control group (C) underwent an osteotomy of the medial femoral condyle, contamination with a slurry of clay mixed with Staphylococcus aureus, stabilization and closure. The bulb syringe and pulsatile groups (B and P) underwent an identical procedure, with the addition of irrigation with 11 of saline by bulb syringe or pulsatile lavage system. Two fluorescent bone stains that mark new bone formation were administered subcutaneously: xylenol orange at the time of surgery and calcein green one week postoperatively. Animals were euthanized two weeks postoperatively and femurs were retrieved for histological analysis. Union was determined by examination of microradiographs. The viability of bone along the osteotomy site in the first and second weeks after irrigation was determined by evaluation of the two fluorescent stains. The density of new bone two weeks after irrigation was assessed by digitization of the microradiographs. Nonunion was present in 77%, 53%, and 43% of animals in groups C, B, and P, respectively. There was an increase in the presence of bands of both fluorescent stains along the osteotomy site in the groups B and P compared to group C. There was no statistically significant difference between groups B and P in either fluorescent stain. On digitization of microradiographs, there was more calcified new bone on postoperative day 14 in group P than in either group B or C (p = 0.04). The addition of contamination and foreign material to an intraarticular fracture model results in lower rates of new bone formation and fracture union. Irrigation in this setting is clearly beneficial, whether the irrigant is delivered by bulb irrigation or by HPPL. The results of this study indicate using HPPL in this setting does not cause greater damage than using bulb syringe irrigation.

Animals↗
PubMed2002

Scoring of orthopaedic residency applicants: is a scoring system reliable?

The purpose of the current study was to examine the interobserver reliability of a scoring system designed to objectify the screening of orthopaedic residency applications. Forty residency applications were selected randomly from those received in 1998 and were scored independently by six observers. The scoring system used included objective and subjective elements. Weights were assigned to individual data elements based on the results of a previous investigation. Interobserver reliability was calculated using an intraclass correlation coefficient. The overall reliability of the scoring system revealed an intraclass correlation coefficient of 0.80. The intraclass correlation coefficients for individual elements in the scoring system ranged from 0.28 to 0.98. The intraclass correlation coefficient was high for elements that were numeric, but was low for elements that were more subjective. Observers thought the scoring form was easy to complete but found some of the subjective data elements difficult to score. No benchmarks exist by which to define an acceptable intraclass correlation coefficient of a scoring model for resident applicants. Even with the use of careful definitions, raters had poor reliability in scoring elements such as letters of recommendation and personal statements. The results of the current study indicate that one score of objective data elements is adequate to screen a residency application for these elements. Programs screening applicants based on subjective elements, however, should be aware that great interobserver variability exists in the interpretation of those elements.

Humans↗
PubMed2002

Correlating selection criteria with subsequent performance as residents.

The objective of this study was to determine which criteria in the residency application had the highest correlation with subsequent performance of orthopaedic residents. Data collected from the application files of 58 residents included scores on standardized tests, number of honors grades in the basic and clinical years of medical school, election to Alpha Omega Alpha, numbers of research projects and publications, and numbers of extracurricular activities. Measures of performance included scores on the Orthopaedic In-Training Examination and American Board of Orthopaedic Surgery Part I Examination, and faculty evaluations of overall, cognitive, affective, and psychomotor performance. The number of honors grades on clinical rotations was the strongest predictor of performance, whereas election to Alpha Omega Alpha was second. The only other significant correlation was between the number of fine motor activities and psychomotor performance. None of the predictor variables had a significant correlation with Orthopaedic In-Training Examination or American Board of Orthopaedic Surgery Examination scores. Consistency between faculty rankings in each of the four categories was supported by regression analysis. From the results of this study, it appears that academic performance in clinical clerkships in medical school is the most predictive of resident performance. Range restriction in the data available for orthopaedic residency applicants, however, likely precludes the development of a reliable model to assist in the selection of orthopaedic residents.

Clinical Competence↗
PubMed2002

Change over time of SF-36 functional outcomes for operatively treated unstable ankle fractures.

OBJECTIVE: Ankle fractures are one of the most common operatively treated lower extremity fractures. Several studies indicate that patients often have residual effects after this injury. The purpose of this study is to use the SF-36 questionnaire at two times to assess patients' functional recovery and residual effects after operative stabilization of an unstable ankle fracture. DESIGN: Twenty adult patients with an isolated unstable ankle fracture (OTA 44B/C) who had operative stabilization completed an SF-36 questionnaire when they were released from orthopaedic follow-up at approximately four months from injury. These same patients again completed the SF-36 at a longer follow-up, twenty months on average. Both SF-36 scores were compared with U.S. population norms. SETTING: Level II Community Hospital. INTERVENTION: Internal fixation of unstable ankle fractures. MAIN OUTCOME MEASURES: SF-36 questionnaire. RESULTS: Patients had significant improvement (p < 0.5) in all domains of the SF-36 questionnaire at the later follow-up, except for general health, which was unchanged. Patients still had significant differences in SF-36 scores compared with the U.S. population at the time of release from routine follow-up. The scores of all the domains of the SF-36 at the later follow-up were not significantly different from U.S. population norms except for the domain of physical functioning. CONCLUSIONS: This study indicates that patients have significant improvement in functional outcome after release from orthopaedic follow-up but have a residual physical effect at twenty months after injury. These data are important to guide a patient's expectations after this injury and are also important in considering medicolegal and workers' compensation issues. Patients continue to have improvement in function after we have routinely released them from orthopaedic follow-up. Maximal medical improvement appears to be longer than four months from this injury.

Adolescent↗
PubMed2002

High-pressure pulsatile lavage irrigation of fresh intraarticular fractures: effectiveness at removing particulate matter from bone.

OBJECTIVE: To determine the effectiveness of high-pressure pulsatile lavage (HPL) versus bulb syringe (BS) irrigation in removing particulate matter from metaphyseal cancellous bone. DESIGN: Four grams of particulate graphite were placed in twenty distal femoral intraarticular osteotomies performed on New Zealand rabbit hind limbs. Two groups of ten specimens were then irrigated using either HPL or BS irrigation. A representative coronal section from each specimen was then prepared for histologic evaluation using 400x light microscopy. The number and distribution of graphite particles-present as small (less than 20 micrometers), medium (20 to 50 micrometers), and large (greater than 50 micrometers) aggregates-were then recorded. RESULTS: The mean maximum perpendicular distance of graphite aggregates of all sizes from the osteotomy site was 12.4 millimeters (+/-SD 2.5) in the HPL group and 12.5 millimeters (+/-SD 2.0) in the BS group (p > 0.5). The mean number of aggregates within four 400x fields (1.08 millimeters) of the osteotomy site was 21.9 (+/-SD 22.0) in the HPL group and 21.8 (+/-SD 27.5) in the BS group (p > 0.5). The mean total number of aggregates in the area surveyed was 129.4 (+/-SD 79.6) in the HPL group and 137.5 (+/-SD 113.6) in the BS group (p > 0.5). Separate analyses controlling for aggregate size of the specimens also revealed no significant differences between HPL and BS irrigation. CONCLUSION: HPL and BS irrigation appear equally effective in removing particulate matter from metaphyseal cancellous bone in an intraarticular fracture model. Furthermore, HPL does not appear to drive particulate matter farther into metaphyseal cancellous bone than BS irrigation.

Animals↗
PubMed2002

Mechanical strength and wear of used EBI external fixators.

Thirty-one EBI external fixators (Dynafix; EBI, Parsippany, NJ) subjected to one or two clinical uses underwent static mechanical testing identical to that performed on new devices prior to market approval. No fixator exhibited catastrophic mechanical failure. For all fixators tested, the mean load to failure was not significantly different from that of identical testing of new devices. Although loss of material from serrated joints was observed in some joints, mechanical strength was not affected. Additional testing of fixators of a variety of designs is necessary to expand on the results of this investigation. The results of this study represent a first step in validating the safety of external fixator component reuse.

Equipment Failure↗
PubMedDate not supplied

Debridement of cancellous bone: a comparison of irrigation methods.

OBJECTIVE: This study tests the bone debridement efficacy and damage to cancellous bone produced by different wound irrigation methods. METHODS: Cancellous bone slices of bovine distal femurs (3 cm x 3 cm) were divided into eight test groups and scored with a saw in a latticed pattern. Four test groups were contaminated with 1.0 g rock dust and four were not. The specimens were then treated as follows: no treatment (control), bulb irrigation, brush-suction irrigation, or high-pressure pulsatile lavage (HPPL). Runoff from the irrigation was collected, filtered, lyophilized, and ashed to allow for quantitative determination of organic and inorganic material removed from the bone by each irrigation method. The bone samples were subjected to blinded grading on two five-point scales to assess: 1) macroscopic tissue damage and 2) amount of contaminant remaining following treatment. RESULTS: Significantly more (P < or = 0.05) mean organic material was removed from samples treated with HPPL (744.8 +/- 120.0 mg) than with bulb syringe (115.2 +/- 11.9 mg) or brush-suction irrigation (95.1 +/- 9.2 mg). Brush-suction irrigation removed statistically significantly more (P < or = 0.05) of the 1.0 g of initial inorganic contaminant (937.7 +/- 6.3 mg) than bulb syringe irrigation (866.2 +/- 30.1 mg), while HPPL (900.2 +/- 19.0 mg) did not. CONCLUSIONS: Past studies have shown HPPL to damage both soft tissue and bone structure. The tissue damage that HPPL produces has been accepted in the past in exchange for its presumed superiority in contaminant removal. In this study, HPPL damaged samples more than other irrigation methods by removing significantly more organic material from them. However, HPPL and bulb syringe removed a statistically similar amount of inorganic contaminant, while brush-suction irrigation removed a significantly greater amount of inorganic contaminant than bulb syringe. It is proposed that HPPL may drive some contaminants deeper into the tissue rather than removing them, rendering HPPL not only more deleterious to bone structure and healing, but also less efficacious at removing contaminant than brush-suction irrigation.

Animals↗